In Japanese mythology, this species is considered a deceptive shape-shifter that preys on young, handsome men—hence its name jorō-gumo, which means "binding bride" or "whore spider." In Korea, the arachnid's name is mudang gumi, which translates to "shaman" or "fortune-teller" spider.

But in real life, so-called Joro spiders are not harmful to humans, and there's no evidence—at least not yet—that their presence has had a negative impact on U.S. ecosystems.

"It knocked my socks off, to some extent, when I saw the first image," says study leader E. Richard Hoebeke, curator of arthropods at the Georgia Museum of Natural History.

New Kid on the Block

Adult female N. clavata are spectacular sights, with striped legs and abdomens that appear as though they've been dipped in a pool of swirling yellow, red, and black paint. In contrast, the males are a relatively colorless brown, and like males throughout the Nephila genus, are dwarfed by the females.

After that incident, Huffmaster, Hoebeke, and colleagues began looking for more such suspicious spiders. Over ten days, the team collected or spotted about a dozen Joro spiders and their tough webs in three counties—a wide distribution that suggests the spiders are successfully setting up shop on their new continent.

The team verified the critters' identities photographically and with DNA testing, which indicated that the Georgia spiders all came from the same source in China or Japan.

What is unusual—but not unheard of—is for spiders to establish populations at their destinations. When this happens, as withSteatoda nobilis in southern California, it's normally near large ports; but the Georgian counties are nowhere near a port.

"Spiderlings of this particular group are really good dispersers because of the way they're able to spin a piece of silk," Hoebeke says. "It kind of acts like a parachute, if you will, and gets dragged by the prevailing wind currents."

Finding Joro

It's too soon to say how big the North American N. clavata population is and whether the spider is likely to compete with native species. The vibrant new arrival does have an American relative: Nephila clavipes, a golden silk orb weaver that's native to the southern U.S.

"I suspect it may be more widespread than what our data is initially indicating," Hoebeke says. "It could be anywhere where there are major importing warehouses."

Now, with winter waning and spring on the way, the spiders are about to emerge from their egg sacs. They'll grow over the next few months and be easiest to spot in late summer or early fall.

Hoebeke is hoping for some help in finding them.

"We can't be everywhere looking for this thing, but we can have people take a close look and let us know," he says.